Alzheimer's disease

We have selected the following expert medical opinion based on its clarity, reliability and accuracy. Credits: Sourced from the Mayo Clinic, Minnesota. Please refer to your own medical practitioner for a final perspective, assessment or evaluation.

Overview

Alzheimer's disease is a progressive disease that destroys memory and other important mental functions. At first, someone with Alzheimer's disease may notice mild confusion and difficulty remembering. Eventually, people with the disease may even forget important people in their lives and undergo dramatic personality changes.

Alzheimer's disease is the most common cause of dementia — a group of brain disorders that cause the loss of intellectual and social skills. In Alzheimer's disease, the brain cells degenerate and die, causing a steady decline in memory and mental function.

Current Alzheimer's disease medications and management strategies may temporarily improve symptoms. This can sometimes help people with Alzheimer's disease maximize function and maintain independence for a little while longer, but because there's no cure for Alzheimer's disease, it's important to seek supportive services and tap into your support network as early as possible.

Symptoms

At first, increasing forgetfulness or mild confusion may be the only symptoms of Alzheimer's disease that you notice. But over time, the disease robs you of more of your memory, especially recent memories. The rate at which symptoms worsen varies from person to person.

If you have Alzheimer's, you may be the first to notice that you're having unusual difficulty remembering things and organizing your thoughts. Or you may not recognize that anything is wrong, even when changes are noticeable to your family members, close friends or co-workers.

Brain changes associated with Alzheimer's disease lead to growing trouble with:

Memory

Everyone has occasional memory lapses. It's normal to lose track of where you put your keys or forget the name of an acquaintance. But the memory loss associated with Alzheimer's disease persists and worsens, affecting your ability to function at work and at home.

People with Alzheimer's may:

• Repeat statements and questions over and over, not realizing that they've asked the question before
• Forget conversations, appointments or events, and not remember them later
• Routinely misplace possessions, often putting them in illogical locations
• Get lost in familiar places
• Eventually forget the names of family members and everyday objects
• Have trouble finding the right words to identify objects, express thoughts or take part in conversations
  
  

Thinking and reasoning

Alzheimer's disease causes difficulty concentrating and thinking, especially about abstract concepts like numbers.

Multitasking is especially difficult, and it may be challenging to manage finances, balance checkbooks and pay bills on time. These difficulties may progress to inability to recognize and deal with numbers.

Making judgments and decisions

Responding effectively to everyday problems, such as food burning on the stove or unexpected driving situations, becomes increasingly challenging.

Planning and performing familiar tasks

Once-routine activities that require sequential steps, such as planning and cooking a meal or playing a favorite game, become a struggle as the disease progresses. Eventually, people with advanced Alzheimer's may forget how to perform basic tasks such as dressing and bathing.

Changes in personality and behavior

Brain changes that occur in Alzheimer's disease can affect the way you act and how you feel.

People with Alzheimer's may experience:

• Depression
• Apathy
• Social withdrawal
• Mood swings
• Distrust in others
• Irritability and aggressiveness
• Changes in sleeping habits
• Wandering
• Loss of inhibitions
• Delusions, such as believing something has been stolen

Many important skills are not lost until very late in the disease. These include the ability to read, dance and sing, enjoy old music, engage in crafts and hobbies, tell stories, and reminisce.

This is because information, skills and habits learned early in life are among the last abilities to be lost as the disease progresses; the part of the brain that stores this information tends to be affected later in the course of the disease. Capitalizing on these abilities can foster successes and maintain quality of life even into the moderate phase of the disease.

Causes

Scientists believe that for most people, Alzheimer's disease is caused by a combination of genetic, lifestyle and environmental factors that affect the brain over time.

Less than 5 percent of the time, Alzheimer's is caused by specific genetic changes that virtually guarantee a person will develop the disease.

Although the causes of Alzheimer's aren't yet fully understood, its effect on the brain is clear. Alzheimer's disease damages and kills brain cells. A brain affected by Alzheimer's disease has many fewer cells and many fewer connections among surviving cells than does a healthy brain.

As more and more brain cells die, Alzheimer's leads to significant brain shrinkage.

When doctors examine Alzheimer's brain tissue under the microscope, they see two types of abnormalities that are considered hallmarks of the disease:

• Plaques: These clumps of a protein called beta-amyloid may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication. Although the ultimate cause of brain-cell death in Alzheimer's isn't known, the collection of beta-amyloid on the outside of brain cells is a prime suspect.
  
  
• Tangles: Brain cells depend on an internal support and transport system to carry nutrients and other essential materials throughout their long extensions. This system requires the normal structure and functioning of a protein called tau. In Alzheimer's, threads of tau protein twist into abnormal tangles inside brain cells, leading to failure of the transport system. This failure is also strongly implicated in the decline and death of brain cells.

Risk factors

Age

Increasing age is the greatest known risk factor for Alzheimer's. Alzheimer's is not a part of normal aging, but your risk increases greatly after you reach age 65. The rate of dementia doubles every decade after age 60.

People with rare genetic changes linked to early-onset Alzheimer's begin experiencing symptoms as early as their 30s.

Family history and genetics

Your risk of developing Alzheimer's appears to be somewhat higher if a first-degree relative — your parent or sibling — has the disease. Scientists have identified rare changes (mutations) in three genes that virtually guarantee a person who inherits them will develop Alzheimer's. But these mutations account for less than 5 percent of Alzheimer's disease.

Most genetic mechanisms of Alzheimer's among families remain largely unexplained. The strongest risk gene researchers have found so far is apolipoprotein e4 (APoE4), though not everyone with this gene goes on to develop Alzheimer's disease. Other risk genes have been identified but not conclusively confirmed.

Down syndrome

Many people with Down syndrome develop Alzheimer's disease. Signs and symptoms of Alzheimer's tend to appear 10 to 20 years earlier in people with Down syndrome than they do for the general population. A gene contained in the extra chromosome that causes Down syndrome significantly increases the risk of Alzheimer's disease.

Sex

Women seem to be more likely than are men to develop Alzheimer's disease, in part because they live longer.

Mild cognitive impairment

People with mild cognitive impairment (MCI) have memory problems or other symptoms of cognitive decline that are worse than might be expected for their age, but not severe enough to be diagnosed as dementia.

Those with MCI have an increased risk — but not a certainty — of later developing dementia. Taking action to develop a healthy lifestyle and strategies to compensate for memory loss at this stage may help delay or prevent the progression to dementia.

Past head trauma

People who've had a severe head trauma seem to have a greater risk of Alzheimer's disease.

Lifestyle and heart health

There's no lifestyle factor that's been definitively shown to reduce your risk of Alzheimer's disease. However, some evidence suggests that the same factors that put you at risk of heart disease also may increase the chance that you'll develop Alzheimer's.

Examples include:

• Lack of exercise
• Obesity
• Smoking or exposure to secondhand smoke
• High blood pressure
• High blood cholesterol
• Poorly controlled type 2 diabetes
• A diet lacking in fruits and vegetables
  
  

These risk factors are also linked to vascular dementia, a type of dementia caused by damaged blood vessels in the brain. Working with your health care team on a plan to control these factors will help protect your heart — and may also help reduce your risk of Alzheimer's disease and vascular dementia.

Lifelong learning and social engagement

Studies have found an association between lifelong involvement in mentally and socially stimulating activities and a reduced risk of Alzheimer's disease. Low education levels — less than a high school education — appear to be a risk factor for Alzheimer's disease.

Complications

Memory and language loss, impaired judgment, and other cognitive changes caused by Alzheimer's can complicate treatment for other health conditions.

A person with Alzheimer's disease may not be able to:

• Communicate that he or she is experiencing pain — for example, from a dental problem
• Report symptoms of another illness
• Follow a prescribed treatment plan
• Notice or describe medication side effects

As Alzheimer's disease progresses to its last stages, brain changes begin to affect physical functions, such as swallowing, balance, and bowel and bladder control.

These effects can increase vulnerability to additional health problems such as:

• Inhaling food or liquid into the lungs (aspiration)
• Pneumonia and other infections
• Falls
• Fractures
• Bedsores
• Malnutrition or dehydration

Prevention

Right now, there's no proven way to prevent Alzheimer's disease. Research into prevention strategies is ongoing.

The strongest evidence so far suggests that you may be able to lower your risk of Alzheimer's disease by reducing your risk of heart disease.

Many of the same factors that increase your risk of heart disease can also increase your risk of Alzheimer's disease and vascular dementia. Important factors that may be involved include high blood pressure, high blood cholesterol, excess weight and diabetes.

The Mediterranean diet — a way of eating that emphasizes fresh produce, healthy oils and foods low in saturated fat — can lower the risk of death from cardiovascular disease and stroke. This diet has also been associated with a reduced risk of Alzheimer's disease.

Keeping active — physically, mentally and socially — may make your life more enjoyable and may also help reduce the risk of Alzheimer's disease.

Diagnosis

There's no specific test today that confirms you have Alzheimer's disease. Your doctor will make a judgment about whether Alzheimer's is the most likely cause of your symptoms based on the information you provide and results of various tests that can help clarify the diagnosis.

Doctors can nearly always determine whether you have dementia, and they can often identify whether your dementia is due to Alzheimer's disease. Alzheimer's disease can be diagnosed with complete accuracy only after death, when microscopic examination of the brain reveals the characteristic plaques and tangles.

To help distinguish Alzheimer's disease from other causes of memory loss, doctors now typically rely on the following types of tests:

Physical and neurological exam

Your doctor will perform a physical exam, and is likely to check your overall neurological health by testing your:

• Reflexes
• Muscle tone and strength
• Ability to get up from a chair and walk across the room
• Sense of sight and hearing
• Coordination
• Balance
  
  

Lab tests

Mental status and neuropsychological testing

Your doctor may conduct a brief mental status test to assess your memory and other thinking skills. In addition, your doctor may suggest a more extensive assessment of your thinking and memory. Longer forms of neuropsychological testing may provide additional details about your mental function compared with others of a similar age and education level.

Brain imaging

Images of the brain are now used chiefly to pinpoint visible abnormalities related to conditions other than Alzheimer's disease — such as strokes, trauma or tumors — that may cause cognitive change. New imaging applications — currently used primarily in major medical centers or in clinical trials — may enable doctors to detect specific brain changes caused by Alzheimer's.

Brain-imaging technologies include:

Magnetic resonance imaging (MRI): An MRI uses radio waves and a strong magnetic field to produce detailed images of your brain. MRIs are used to rule out other conditions that may account for or be adding to cognitive symptoms. In addition, they may be used to assess whether shrinkage in brain regions implicated in Alzheimer's disease has occurred.

Computerized tomography (CT): A CT scan produces cross-sectional images (slices) of your brain. It's currently used chiefly to rule out tumors, strokes and head injuries.

Positron emission tomography (PET): During a PET scan, you'll be injected in a vein with a low-level radioactive tracer. The tracer may be a special form of glucose (sugar) that shows overall activity in various brain regions.

This can show which parts of your brain aren't functioning well. New PET techniques are able to detect your brain level of plaques (amyloid) and tangles (tau), the two hallmark abnormalities linked to Alzheimer's. However, these new PET techniques are generally found in research settings or in clinical trials.

Cerebrospinal fluid: In special circumstances such as rapidly progressive dementia or very young onset dementia, a cerebrospinal fluid examination may be performed. The spinal fluid can be tested for biomarkers that indicate the likelihood of Alzheimer's disease.

Future diagnostic tests

Researchers are working with doctors to develop new diagnostic tools to help definitively diagnose Alzheimer's. Another important goal is to detect the disease before it causes the symptoms.

New tools under investigation include:

• Additional approaches to brain imaging
• More-sensitive tests of mental abilities
• Measurement of key proteins or protein patterns in blood or spinal fluid (biomarkers)

Genetic testing generally isn't recommended for a routine Alzheimer's disease evaluation. The exception is people who have a history of early-onset Alzheimer's disease. However, anyone with a family history of early Alzheimer's needs to meet with a genetic counselor to discuss the risks and benefits of genetic testing.

Treatment

Drugs

Current Alzheimer's medications can help for a time with memory symptoms and other cognitive changes.

Two types of drugs are currently used to treat cognitive symptoms:

Cholinesterase inhibitors: These drugs work by boosting levels of a cell-to-cell communication by providing a neurotransmitter (acetylcholine) that is depleted in the brain by Alzheimer's disease. The improvement is modest. Cholinesterase inhibitors can improve neuropsychiatric symptoms, such as agitation or depression, as well.

Commonly prescribed cholinesterase inhibitors include donepezil (Aricept), galantamine (Razadyne) and rivastigmine (Exelon). The main side effects of these drugs include diarrhea, nausea, loss of appetite and sleep disturbances. In people with cardiac conduction disorders, serious side effects may include a slow heart rate and heart block.

Memantine (Namenda): This drug works in another brain cell communication network and slows the progression of symptoms with moderate to severe Alzheimer's disease. It's sometimes used in combination with a cholinesterase inhibitor. Side effects may include constipation, dizziness and headache.

Sometimes other medications such as antidepressants are used to help control the behavioral symptoms associated with Alzheimer's disease. But some medications should only be used with great caution. For example, some common sleep medications — zolpidem, eszopiclone and others — may increase confusion and the risk of falls.

Anti-anxiety medications — clonazepam and lorazepam — increase the risk of falls, confusion and dizziness. Always check with your doctor before taking any new medications.

Creating a safe and supportive environment

Adapting the living situation to the needs of a person with Alzheimer's is an important part of any treatment plan. For someone with Alzheimer's, establishing and strengthening routine habits and minimizing memory-demanding tasks can make life much easier.

You can take these steps to support a person's sense of well-being and continued ability to function:

• Always keep keys, wallets, mobile phones and other valuables in the same place at home, so they don't become lost.
• See if your doctor can simplify your medication regimen to once-daily dosing and arrange for your finances to be on automatic payment and automatic deposit.
• Develop the habit of carrying a mobile phone with location capability so that you can call in case you are lost or confused, and people can track your location via the phone. Also, program important phone numbers into your phone, so you don't have to try to recall them.
• Make sure regular appointments are on the same day at the same time as much as possible.
• Use a calendar or whiteboard in the home to track daily schedules. Build the habit of checking off completed items so that you can be sure they were completed.
• Remove excess furniture, clutter and throw rugs.
• Install sturdy handrails on stairways and in bathrooms.
• Ensure that shoes and slippers are comfortable and provide good traction.
• Reduce the number of mirrors. People with Alzheimer's may find images in mirrors confusing or frightening.
• Keep photographs and other meaningful objects around the house.

Exercise

Regular exercise is an important part of everybody's wellness plan — and those with Alzheimer's are no exception. Activities such as a daily walk can help improve mood and maintain the health of joints, muscles and the heart.

Exercise can also promote restful sleep and prevent constipation. Make sure that the person with Alzheimer's carries identification or wears a medical alert bracelet if she or he walks unaccompanied.

People with Alzheimer's who develop trouble walking may still be able to use a stationary bike or participate in chair exercises. You may be able to find exercise programs geared to older adults on TV or on DVDs.

Nutrition

People with Alzheimer's may forget to eat, lose interest in preparing meals or not eat a healthy combination of foods. They may also forget to drink enough, leading to dehydration and constipation.

Offer:

• High-calorie, healthy shakes and smoothies: You can supplement milkshakes with protein powders (available at grocery stores, drugstores and discount retailers) or use your blender to make smoothies featuring your favorite ingredients.
• Water, juice and other healthy beverages: Try to ensure that a person with Alzheimer's drinks at least several full glasses of liquids every day. Avoid beverages with caffeine, which can increase restlessness, interfere with sleep and trigger a frequent need to urinate.
  
  

Certain nutritional supplements are marketed as "medical foods" specifically to treat Alzheimer's disease. The Food and Drug Administration (FDA) does not approve products marketed as medical foods. Despite marketing claims, there's no definitive data showing that any of these supplements is beneficial or safe.

Lifestyle and home remedies

Study results have been mixed about whether diet, exercise or other healthy lifestyle choices can prevent or reverse cognitive decline. But these healthy choices promote good overall health and may play a role in maintaining cognitive health, so there's no harm in including these strategies in your general wellness plan:

• Regular exercise, especially cardiovascular exercise, has known benefits for heart health and may also help prevent cognitive decline. Exercise may also help improve mood.
  
  
• A diet low in fat and rich in fruits and vegetables is another heart-healthy choice that also may help protect cognitive health.
  
  
• Social engagement and intellectual stimulation may make life more satisfying and help preserve mental function.

Alternative medicine

Various herbal mixtures, vitamins and other supplements are widely promoted as preparations that may support cognitive health or prevent or delay Alzheimer's. Currently, there's no strong evidence that any of these therapies slow the progression of cognitive decline.

Some of the treatments that have been studied recently include:

• Omega-3 fatty acids: Omega-3 fatty acids in fish may help prevent cognitive decline. Studies done on fish oil supplements haven't shown any benefit, however.
  
  
• Curcumin: This herb comes from turmeric and has anti-inflammatory and antioxidant properties that might affect chemical processes in the brain. So far, clinical trials have found no benefit for treating Alzheimer's disease.
  
  
• Ginkgo: Ginkgo is a plant extract containing several substances. A large study funded by the NIH found no effect in preventing or delaying Alzheimer's disease.
  
  
• Vitamin E: Although vitamin E isn't effective for preventing Alzheimer's, taking 2,000 international units daily may help delay the progression in people who already have the disease. However, study results have been mixed, with only some showing this benefit. Further research into the safety of 2,000 international units daily of Vitamin E in a dementia population will be needed before it can be routinely recommended.

Supplements promoted for cognitive health can interact with medications you're taking for Alzheimer's disease or other health conditions. Work closely with your health care team to create a treatment plan that's right for you. Make sure you understand the risks and benefits of everything it includes.

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